From the White House:

GENERAL NOTES

All years referenced for economic data are calendar years unless otherwise noted. All years referenced for budget data are fiscal years unless otherwise noted.

At the time of this writing, only three of the appropriations bills for 2009 had been enacted; therefore, references to 2009 spending in the text and tables reflect approximate estimates of final likely appropriations action that set total discretionary funding at the level assumed to conform to the total level for appropriations in the Concurrent resolution on the Budget for 2009. Adjustments are also made to include the costs of the just-enacted American recovery and reinvestment Act of 2009.